Portable power source



FIG. 1 is a top, front, right side perspective view of a portable power source showing our new design;

FIG. 2 is a top, rear, left side perspective view thereof, shown in an alternate position of use;

FIG. 3 is a top, front, right side perspective view thereof, shown in a second alternate position of use;

FIG. 4 is a top, rear, left side perspective view thereof;

FIG. 5 is a bottom, front, left side perspective view thereof, shown in a closed, stored position of use; and,

FIG. 6 is a bottom, front, left side perspective view thereof, shown in an open stored position of use.

The broken lines in the drawings depict portions of the portable power source that form no part of the claimed design. 

CLAIM The ornamental design for a portable power source, as shown and described. 